[PATCH net-next 1/2] sunrpc: do not pull udp headers on receive

[Willem de Bruijn]

From: Willem de Bruijn <will...@google.com>

Commit e6afc8ace6dd modified the udp receive path by pulling the udp
header before queuing an skbuff onto the receive queue.

Sunrpc also calls skb_recv_datagram to dequeue an skb from a udp
socket. Modify this receive path to also no longer expect udp
headers.

Fixes: e6afc8ace6dd ("udp: remove headers from UDP packets before queueing")

Reported-by: Franklin S Cooper Jr. <fcoo...@ti.com>
Signed-off-by: Willem de Bruijn <will...@google.com>
---
 net/sunrpc/socklib.c  | 2 +-
 net/sunrpc/svcsock.c  | 5 ++---
 net/sunrpc/xprtsock.c | 5 ++---
 3 files changed, 5 insertions(+), 7 deletions(-)

diff --git a/net/sunrpc/socklib.c b/net/sunrpc/socklib.c
index 2df87f7..8ab40ba 100644
--- a/net/sunrpc/socklib.c
+++ b/net/sunrpc/socklib.c
@@ -155,7 +155,7 @@ int csum_partial_copy_to_xdr(struct xdr_buf *xdr, struct 
sk_buff *skb)
        struct xdr_skb_reader   desc;
 
        desc.skb = skb;
-       desc.offset = sizeof(struct udphdr);
+       desc.offset = 0;
        desc.count = skb->len - desc.offset;
 
        if (skb_csum_unnecessary(skb))
diff --git a/net/sunrpc/svcsock.c b/net/sunrpc/svcsock.c
index 1413cdc..71d6072 100644
--- a/net/sunrpc/svcsock.c
+++ b/net/sunrpc/svcsock.c
@@ -617,7 +617,7 @@ static int svc_udp_recvfrom(struct svc_rqst *rqstp)
        svsk->sk_sk->sk_stamp = skb->tstamp;
        set_bit(XPT_DATA, &svsk->sk_xprt.xpt_flags); /* there may be more 
data... */
 
-       len  = skb->len - sizeof(struct udphdr);
+       len  = skb->len;
        rqstp->rq_arg.len = len;
 
        rqstp->rq_prot = IPPROTO_UDP;
@@ -641,8 +641,7 @@ static int svc_udp_recvfrom(struct svc_rqst *rqstp)
                skb_free_datagram_locked(svsk->sk_sk, skb);
        } else {
                /* we can use it in-place */
-               rqstp->rq_arg.head[0].iov_base = skb->data +
-                       sizeof(struct udphdr);
+               rqstp->rq_arg.head[0].iov_base = skb->data;
                rqstp->rq_arg.head[0].iov_len = len;
                if (skb_checksum_complete(skb))
                        goto out_free;
diff --git a/net/sunrpc/xprtsock.c b/net/sunrpc/xprtsock.c
index 65e7595..c1fc7b2 100644
--- a/net/sunrpc/xprtsock.c
+++ b/net/sunrpc/xprtsock.c
@@ -995,15 +995,14 @@ static void xs_udp_data_read_skb(struct rpc_xprt *xprt,
        u32 _xid;
        __be32 *xp;
 
-       repsize = skb->len - sizeof(struct udphdr);
+       repsize = skb->len;
        if (repsize < 4) {
                dprintk("RPC:       impossible RPC reply size %d!\n", repsize);
                return;
        }
 
        /* Copy the XID from the skb... */
-       xp = skb_header_pointer(skb, sizeof(struct udphdr),
-                               sizeof(_xid), &_xid);
+       xp = skb_header_pointer(skb, 0, sizeof(_xid), &_xid);
        if (xp == NULL)
                return;
 
-- 
2.8.0.rc3.226.g39d4020